From finger movements to Spotify

Bilateral stimulation is best known today through its use in EMDR, but its origins are surprisingly simple.

An observation while walking

In the late 1980s, psychologist Francine Shapiro noticed something unexpected during a period of personal illness. While walking outdoors, she observed that as her eyes moved naturally from left to right, the intensity of her worrying thoughts decreased. When she deliberately recreated these eye movements later, the effect appeared to repeat.

Intrigued, she began experimenting — first on herself, then with family and friends. Rhythmic left–right eye movements seemed to reduce emotional distress. This observation eventually became the foundation of EMDR (Eye Movement Desensitization and Reprocessing).

Why external stimulation was necessary

One practical problem became clear early on: under stress, people are generally unable to guide their own eye movements in a steady left–right rhythm. Concentration falters, attention collapses inward, and voluntary control breaks down.

To solve this, Shapiro introduced an external stimulus. Most commonly, this took the form of a therapist moving their hand in front of the client’s eyes so the movement could be followed without effort. This ensured that the bilateral rhythm was present even when the client was emotionally activated.

From the beginning, bilateral stimulation depended on external rhythm.

The rise of workarounds

As EMDR and related approaches spread, many alternative ways of delivering bilateral stimulation emerged.

In mass-trauma and self-help contexts, people are often taught simple tapping techniques such as the “butterfly hug” or tapping on the knees. These methods are portable, discreet, and can be used in public or under acute stress. They are especially valuable in situations where no therapist or equipment is available.

Audio-only bilateral stimulation later became widespread. Thousands of alternating left–right sound tracks are now available on platforms like Spotify and YouTube. Some people combine these with visual cues on screens, while others use dedicated devices such as tactile tappers or light bars designed specifically for bilateral stimulation.

A particularly inventive set of solutions combines multiple consumer devices — for example, pairing a phone with a smartwatch to deliver audio and tactile input together.

Useful — but limited

All of these approaches are useful, and many people benefit from them. At the same time, they share common limitations.

Most stimulate a single sensory channel at a time, or rely on fragile combinations of devices that were never designed to work together. Dedicated hardware can be expensive, prone to battery failure or cable issues, and inconvenient to set up. Screen-based visual stimulation is constrained by the size of a phone or laptop display. Self-tapping techniques are inherently weak and inconsistent as stimuli.

In practice, these tools are workarounds — adaptations built around constraints rather than integrated systems.

Why multi-sensory stimulation matters

There are two main reasons clinicians and researchers have explored combining multiple forms of bilateral stimulation.

First, people differ in how they respond to sensory input. Some respond strongly to visual stimulation, others to sound or touch. A multi-modal approach makes bilateral stimulation accessible to a broader range of individuals.

Second, and more importantly, there is a working hypothesis inspired by research on EMDR and working-memory taxation. Engaging multiple sensory channels simultaneously may place a higher load on working memory. When working memory is sufficiently occupied by rhythmic, alternating input, fewer cognitive resources remain available for rumination, worry, or intrusive thought patterns.

One possible consequence is that settling or relaxation can occur very quickly, often during use rather than after it. This hypothesis is still being explored and does not imply uniform effects for everyone.

What virtual reality changes

Virtual reality removes many of the constraints that shaped earlier solutions.

It allows visual, auditory, and haptic bilateral stimulation to be delivered together, in a synchronized way, within a single system. It also makes it possible to place users directly inside a calming environment rather than relying on imagination alone.

Nothing else currently combines multi-sensory bilateral stimulation with immediate, embodied safe-place immersion. This combination is the core reason Waven is built in VR.

An open question

Waven began as a personal tool, informed by long-term experience with bilateral stimulation in therapeutic contexts. Today, it exists as an open question: can carefully delivered bilateral stimulation in virtual reality be useful for more people, and if so, under what conditions?

Answering that question requires restraint, research, and time. This article is part of that process.